Over Voltage Category III Power Supplies Giacomo Mazzullo

BDM – MEAN WELL EUROPE BV

Agenda

• Lighting Types

• Lighting Waveforms

• Over Voltage Category Definition

• Testing Table

• Impulse vs Withstand

• OVC III Applications

• MW Products meeting OVC III

• Modified products to meet OVC III

• 61558 and OVC III

• OVC III and Altitude

• How to use OVC II PSU in OVC III Applications

• Conclusions

Lighting Types

Lighting Waveforms

Lighting Waveforms

Over Voltage Category Definition in Power Supplies

Over Voltage Category Definition

OVC III Equipment is downward compatible with OVC II, I

application and environment.

Over Voltage Category Definition

I. Equipment of Overvoltage Category I (OVC I) is equipment for connection to circuits in which

measures are taken to limit transient or short duration overvoltage to an appropriately low level.

• The typical application is equipment containing electronic circuits protected to this level.

II. Equipment of Overvoltage Category II (OVC II) is energy-consuming equipment to be supplied

from the fixed installation.

• The typical application is appliances, portable tools and other household similar loads.

III. Equipment of Overvoltage Category III (OVC III) is equipment in fixed installations and for cases

where the reliability and the availability of the equipment is subject to special requirements.

• The typical application is switch(es) in the fixed installation and equipment for industrial

use with permanent connection to the fixed installation.

IV. Equipment of Overvoltage Category IV (OVC IV) is for use at the origin of the installation.

• The typical application is electricity meter(s) and primary overcurrent protection

equipment.

Voltage line to neutral derived from

nominal voltage AC or DC up to and

including (V)

Rated impulse voltage (V)

Overvoltage category

I II III IV

50 330 500 800 1500

100 500 800 1500 2500

150 800 1500 2500 4000

300 1500 2500 4000 6000

600 2500 4000 6000 8000

1000 4000 6000 8000 12000

Table 1 shows only the level for basic insulation.

In case the power supply is designed to double or reinforced insulation,

the voltage should consider one level higher.

For example:

For unit operating at 300Vac• OVC II is tested @ 2500V for basic and 4000 for double (SELV)

Over Voltage Category Testing Table

OVC Impluse voltage from table is the Peak Value

Withstand voltage is RMS value

The peak of withstand voltage is √2 x VRMS = 1.414 x VRMS

Withstand voltage test is 1 min continous -> Withstand voltage test is tougher than impluse voltage test!

Impulse vs Withstand

OVC III and Altitude

Some robot controller products to meet the

IEC60204-1 standard need an additional AC transformer in series between the power grid and power supply

OVC III Applications

Name

IEC/EN50178 Electronic equipment for use in power installations

IEC 60204-1 Safety of machinery - Electrical equipment of machines - Part 1: General requirements

IEC 62103 Electronic equipment for use in power installations (replaced by IEC 62477-1)

IEC/EN62477-1 Safety requirements for power electronic converter systems and equipment - Part 1: General

OVC III is equipment in fixed installations and

for cases where the reliability and the

availability of the equipment is subject to

special requirements.

The typical application is switch(es) in the fixed installation

and equipment for industrial use

with permanent connection to the fixed installation.

OVC III Applications

• With EN61558 certificate:

• LRS-35/50/75/100/150/150F• RSP-75/100/150

• HDR-15/30/60/100• KNX-20E

• OWA series• UHP-200/350 with design refer to 61558

MW Products meeting OVC III

Only Medical(EN60601) OVC II product has chance to meet OVC III of 61558.

60950 (OVC II)

61347 (OVC II)60335 (OVC II)

Modified products to meet OVC III

Next version (third edition) of IEC 61558-1 will clearly specify the OVC

test difference among categories to improve the information provide by current release of standard.

IEC 61558-1: 2005 + AMD1: 2009

61558 and OVC III

New product for industrial

application will have it (at least design refer to)

PSU with 61558 OVC III <= 2000m<2000m then downgrade to OVC II

Although the product has reserved the enough clearance distance for 5000m

(1.48 factor larger than 2000m one), but the product also needs to be

subjected to the corresponding impulse voltage test according to IEC61558.

Impulse test of unit is done at 6KV(double insulation) for up to 2000m

>2000m there is not defined in the standard.

So move back to OVCII where the test voltage is 4KV(double insulation)

Then 5000m should be tested 4 x 1.48 = 5.92KV -> NO problem!!

OVC III and Altitude

How to use OVC II PSU in OVC III Applications

How to use OVC II PSU in OVC III Applications

• Power Supply in the market generally refer to OVC II

• If a PSU comply with EN61558 certificate (or design refer to), we can be sure it

is a OVC III unit

• OVC III PSU can be used in OVC II & I application

• MEAN WELL support its customers with PSUs designed to support OVC III

• Where to find OVC info?

• Check the spec about the OVC III or 61558

Conclusions